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arXiv · 2311.06975

A QFT scalar toy model analogous to positronium and pion decays

Milena Piotrowska·Francesco Giacosa
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Abstract

In the framework of a scalar QFT, we evaluate the decay of an initial massive state into two massless particles through a triangle-shaped diagram in which virtual fields propagate. Under certain conditions, the decaying state can be seen as a bound state, thus it is analogous to the neutral pion (quark-antiquark pair) and to the positronium (electron-positron pair), which decay into two photons. While the pion is a relativistic composite object, the positronium is a non-relativistic compound close to threshold. We exam similarities and differences between these two types of bound states.

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Milena Piotrowska, Francesco Giacosa. 2023-11-12. A QFT scalar toy model analogous to positronium and pion decays. https://arxiv.org/abs/2311.06975

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